In the past fifty years, the car crash death rate has dropped by nearly 80 percent in the United States. And one of the reasons for that drop has to do with the “accident report forms” that police officers fill out when they respond to a wreck. Officers use these forms to document the weather conditions, to draw a diagram of the accident, and to identify the collision’s “primary cause.” All that information gathered on the side of the road goes from the accident report form into a federal database: the Fatality Analysis Reporting System.

Car companies, safety advocates, and regulators comb through this data constantly, looking for patterns that help them understand how and why people die in car wrecks. In turn, this information helps designers and engineers create safer vehicles and roadways. The data informs all kinds of design decisions around car safety — everything from speed limits to mandatory seat belts.

But this culture of heavily regulated, data-driven, auto-safety engineering did not always exist. In fact, for decades, automakers tried to keep data about car wrecks to themselves. They not only resisted making cars safer, they argued the very idea of a “safe car” was impossible.